In a heavy 3 quart saucepan, combine the milk and 1/4 cup of sugar. Bring to a gentle simmer over medium heat.

Meanwhile, whisk the egg yolks, egg, cornstarch and remaining 1/3 cup of the sugar together in a mixing bowl until thick and yellow.

Very gradually, whisk the hot milk mixture into the egg yolks. Once it is all added, pour the mixture back into the saucepan with the saucepan set over medium low heat.

Whisk mixture over medium low heat until it is as thick as pudding and starts to boil (thick, gloppy bubbles will appear. If your mixture doesn't thicken in 5 minutes, raise the heat a tiny bit. Different stoves and gas vs. heat might affect the rate at which your cream thickens).

Set a sieve over a clean bowl and pour the pudding through the sieve and into the bowl. Add the butter and vanilla to the hot pudding and stir well.

Put a circle of parchment paper over the mixture to keep a skin from forming and let cool at room temperature for about 30 minutes. Transfer to the refrigerator.

If you want to lighten the texture or make it less sweet, whip 1/2 cup to 1 cup of whipped cream and fold it into the cooled cream. If you add the extra whipping cream, you might also want to throw in a little extra vanilla extract.

Notes

Most pastry cream recipes tell you to boil and stir the mixture for about 2 minutes before removing it from the heat. This kills the enzymes in the eggs which cause the pastry cream to thin out after cooling. Out of habit, I lboiled the cream for an extra minute and a half for the first batch. It did not thin out, nor did it taste starchy. I made a second batch and skipped the extra minute of boiling. The second batch didn't thin out or taste starchy either. I'd say this is a pretty fool-proof recipe, but if you do have problems with thinning or a starchy taste, try boiling the mixture for another minute and a half and stirring constantly to prevent curdling.

Recipe by Cookie Madness at http://www.cookiemadness.net/2013/09/basic-pastry-cream-1/